Immersion-type heater



May 23, 1950 e. GRINDE IMMERSION-TYPE HEATER Filed Jan. 13, 1949 jzaezzzar Geo/ye 67 2/2549 Patented May 23, 1950 IMMERSION-TYPE HEATER George Grinde, Minneapolis, Minn., assignor to Phillips Manufacturing Company, Inc., Minneapolis, Minn., a corporation of Minnesota Application January 13, 1949, Serial No. 70,627

1 Claim.

My invention relates generally to immersion type heaters and, more specifically, to heaters of this type which are adapted to be inserted into the crank case oil of an internal combustion engine through the oil level measuring stick opening.

The primary object of my invention is the provision of a heater of the class above-described, which is extremely highly eificient and fool-proof in use, and which can be operated at a minimum of cost.

Another object of my invention is the provision of a device of the class described, which is relatively inexpensive to produce, and which is rugged in construction.

The above and still further important objects of my invention will become apparent from the following detailed specification, appended claim, and attached drawings.

Referring to the drawings, wherein like characters indicate like parts throughout the several views:

Fig. 1 is a fragmentary section 01' the crank case of an internal combustion engine showing my novel heater in a normal operating position;

Fig. 2 is an enlarged view partly in side elevation and partly in axial section of my novel heater, some parts being broken away;

Fig. 3 is a fragmentary view on a greatly enlarged scale, partly in section and partly in elevation, taken substantially on the line 33 of Fig. 2;

Fig. 4 is a view partly in side elevation and partly in section, taken substantially on the line 4-4 of Fig. 2, also on a greatly enlarged scale;

Fig. 5 is a fragmentary view, partly in axial section and partly in side elevation on an enlarged scale, taken substantially on the line 5--5 of Fig. 2; and

Fig. 6 is a transverse section, taken on the line 6-6 of Fig. 4.

Referring with greater particularity to the drawings, the numeral I indicates an elongated tubular casing preferably formed from metal and having a closed end 2, and an upper end portion 3. The upper end 3 is closed by insulating conduit means 4 in the nature of a cable having therein a pair of lead wires 5 and 6. As shown, the cable 4 is held in the end 3 of the casing I by crimping, as indicated at I, adjacent the upper end. A refractory insulating member, preferably and as shown, comprising a plurality of cooperating sections 8, extends from a. point spaced from but adjacent to the lower end 2 of the casing l upwardly for a distance greater than one-half ll the length of said casing. As shown, particularly in Figs. 3 and 5, the sections 8 comprising the insulating means are provided with aligned pairs of spaced longitudinally-extending passages 9 through which extends, a preferably coiled electrical heating element I0. Heating element [0 is preferably made from conventional material such as Nichrome wire or the like and passes downwardly through one of the passages a in each of the aligned sections 8, across the lower end of the lowermost section 8, as indicated at H, to and upwardly through the other of the passages 9 in the sections 8.

It will be seen, by reference to Fig. 3, that the opposite ends of heating element In terminate adjacent the upper end of the top insulating section 8 and are there soldered or otherwise secured, as indicated at l2, to the lower ends of a pair of leads l3. Leads l3 are covered with asbestos or like insulation, as indicated by l4, and are bound together adjacent their lower ends by a winding of insulating tape IS. The coils of heating element wire In are under slight tension to maintain the tape I5 in close proximity to the top of the upper insulating section 8. As shown particularly by Figs. 2 and 4, the leads I3 are generally centered within the casing l and are connected at their upper ends to wires 5 and 6 of the conduit 4, as indicated at l6 and M respectively.

Generally U-shaped connector clamps l8 are preferably used to effect a greater electrical conductivity between the upper ends of the leads l3 and the wires 5 and 6. The lower end of the conduit 4 and the upper ends of the leads [3, including the connectors l8, are encompassed by a short tube of insulating material such as neoprene rubber or the like, as indicated by 19.

The closed bottom 3 comprises a plug 20, a layer of insulating material such as mica or the like 2|, and suitable sealing material such as brass or solder 22. In the assembly of my device and immediately after the elements 8, ll, l3, l9, and 4 have been inserted into the tubular casing I, and the upper end 3 crimped, all as indicated above, the remaining space within the casing I is filled with powdered insulating material such as magnesium oxide 23. It will be noted that the diameter of insulating sections 8 is slightly less than the inner diameter of the casing l and that the space therebetween is also filled with a layer of powdered insulating material 23. When the casing I has been substantially filled with the powdered insulating material 23, the layer of mica 2| and the plug 20 are inserted into the lower end of the casing and the plug 20 is brazed or welded into place. The powdered insulating material 23 efiectively prevents movement of any of the elements Within the casing l and hence precludes any chance of a short circuit therein. Formation of the refractory heating element from a plurality of sections 8 permits some slight bending of the casing without undue breakage. These features combine to produce a relatively fool-proof and durable structure. Preferably leads l3 are also formed from Nichrome wire of greater diameter and less resistance :to electricity than the heating element l0, whereby to maintain relatively cool connections I6 and H.

As shown in Fig. 1, the casing -l is of a diameter to normally permit it to be inserted'into the normally generally vertically-extendedcrank case oil level indicator aperture 24 after the stick has been removed therefrom. As there shown, the lower end 2 then rests upon the bottom of the crank case 25 so that a substantial p0rti0na0f the heated lowerendof thecasing =is submerged withinthe crankcase oil indicated :by the letter A. Also, as

shown in Fig. .1, thefree .endicf :conduit 4 is provided with a conventional conneotorplug 26.

While my novel heater :is ideally adapted for :use in conjunction with internal combustion engines, it should be obviousthat the same has numerous analogous uses; and, while I have shown a preferred embodiment of my invention, it-will be obvious that the :same is capable of structural modification and change in use without-departure from the spirit and scopc of the inventionxas defined in the appended -claim.

What-I claim'is:

Ina device of the class described, an elongated tubular casing closed at its 'lower end, an elongated refractory insulating member extending longitudinally upwardly within said casing from the lower portion thereof a distance greater than one-half the length of the casing, said insulating member having a pair of spaced parallel passages extending longitudinally therethrough, a coiled electrical heating element extending through said passages and having its opposite ends terminating adjacent the upper end :of said insulating member, an insulated electrical conduit telescopically received within the upper end of said casing and closing same, a pair of longitudinally spaced con- .nectors arranged in stepped relationship to each other securing the opposite ends of said heating element to;said conduit within the confines of an insulating tube Within the casing, said connectors ithereby being insulated from one another and said .casing said tubular casing having substantially uniform diameter throughout its length and being inwardly crimped adjacent its upper end whereby to securely hold said conduit therewithin, the internal diameter of said casing being substantially equal to the external diameter or said conduit.

GEORGE GRINDE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,151, i03 Ryce et a1 Aug. 24, 1915 1,359,400 Lightfoot Nov. 16, 1920 1,487,481 Armstrong Dec. 5, 1922 1,804,885 McCartney May 12, 1931 1894;887 Pingrey Jan. 17, 1933 2,088,586 Cole et al Aug. 8. 191 

